WASHINGTON (AP) -- How did George Nader - Lebanese-American businessman, globe-trotting "fixer," convicted child molester - get caught up in special counsel Robert Mueller's investigation?

The answer, it seems, can be found in the shadows, where Nader has long operated.

His long history included intrepid back-channel mediation between Israel and Arab countries - and a 15-year-old pedophilia conviction in Europe that has not been previously reported. But Mueller, in his investigation of President Donald Trump, his campaign and possible wrongdoing connected to Russia, is focused on Nader's role in two high-level get-togethers after the presidential election, according to three people familiar with the case.

Nader was caught in Mueller's web a few days before the anniversary of Trump's inauguration. He was transiting through Dulles International Airport outside Washington, on his way to Trump's Mar-a-Lago resort, when his plans changed - abruptly and involuntarily.

Mueller's investigators stopped him, people familiar with the case said. His electronics were seized and he was then allowed to go see his lawyer. Nader later agreed to cooperate with Mueller's investigation, said the people with knowledge of the case as it pertains to Nader. They weren't authorized to speak publicly on the case and demanded anonymity.

Nader is little known to the public, a man who has led a shadowy existence as a go-between across numerous Middle East capitals and who gave testimony to Mueller's Washington grand jury earlier this month.

Nader joined a meeting at New York's Trump Tower in December 2016 that brought together presidential son-in-law Jared Kushner, chief strategist Steve Bannon - fired by Trump last August - and Mohammed bin Zayed, crown prince of Abu Dhabi and de facto leader of the United Arab Emirates.

A second meeting occurred a month later in the Indian Ocean archipelago of Seychelles and involved Nader, bin Zayed, former Blackwater boss Erik Prince and Kirill Dmitriev, a Russian banker close to President Vladimir Putin.

Nader's record of sexual abuse in Prague appears unrelated to his role in Mueller's probe in the United States; it is unclear whether Mueller's investigators knew about it. One of Nader's lawyers, Sandeep Savla, suggested that information about his record was being leaked to stop him from cooperating.

"This is nothing more than an orchestrated, disgusting scheme by those who are trying to intimidate Mr. Nader into silence. It won't work," he said. "Mr. Nader will continue to answer truthfully questions put to him by the special counsel."

Kathy Ruemmler, who previously served as White House counsel to President Barack Obama, is among the lawyers representing Nader. She declined to answer questions about her client.

A George Nader was convicted by Prague's Municipal Court of 10 cases of sexually abusing minors and sentenced to a one-year prison term in May 2003, court spokeswoman Marketa Puci told The Associated Press on Wednesday. She said the crimes occurred between 1999 and 2002. She said Nader served time in a Prague prison, though it isn't clear how much. He was then ordered expelled.

Puci said Nader was convicted of "moral corruption of minors, sexual abuse and impairing morals," after abusing underage boys.

In one case, Nader requested oral sex from a 14-year-old boy in a room at the Hilton Hotel in Prague, Puci said. After the boy refused, Nader masturbated in front of him and paid him 2,000 koruna - worth about $100 today, she said.

The verdict cites other examples of Nader providing money, jewelry, cellphones, clothes and accommodation for sexual services. The AP was able to see a copy of the verdict, which gives Nader's birthdate as May 15, 1959. Nader was separately accused in Washington, D.C., of child pornography infractions in 1985, but those charges were later dropped. A criminal docket sheet obtained by the AP shows the same birthdate for Nader.

Two people with knowledge of the case confirmed it involved the same Nader now cooperating with Mueller.

Many of Nader's former contacts and onetime friends have noted in recent weeks how they lost touch with him in the early 2000s.

Nader had worked in recent times as an adviser to bin Zayed, one of the most powerful men in the Middle East, according to people who know Nader. The questioning of Nader in the Mueller probe suggests possible interest in UAE relations with Trump's transition team or his administration.

Nader's connections with Trump confidants include Elliott Broidy, a top Republican fundraiser who co-hosted a Tuesday night event attended by the president in Beverly Hills, California.

Earlier this month, several media organizations, including the AP, obtained emails belonging to Broidy, a California-based venture capitalist and the Republican National Committee's deputy finance chairman. They show Broidy emailing Nader with a summary of Broidy's talks with Kushner and Trump in the White House in October 2017, touching on matters including the UAE's bitter dispute with fellow Persian Gulf country Qatar.

Broidy accused Qatar of hacking his emails. The Qataris denied the charge.

"Your government's actions against U.S. citizens will jeopardize your nation's relationship with the United States," Broidy wrote in a public letter to Qatar's U.S. ambassador.

In response, the Qatari government called Broidy's "baseless accusations" a "diversionary tactic."